


In Deep Water

by NonstopCreatorOfNonsense



Category: Undertale (Video Game)
Genre: Aggression, Alternate Universe, Alternate Universe - Canon, Alternate Universe - Gods & Goddesses, Angst, Angst and Tragedy, Blood, Blood and Injury, Blood and Violence, Bloodlust, Brothers, Cannibalism, Curses, Deities, Feral Behavior, Gen, Gill Papyrus, Killing, Loss of Limbs, Mental Breakdown, Mental Instability, Murder, Neptune Sans, Original Character(s), Originally Posted on Tumblr, Protective Older Brothers, Protectiveness, Punishment, Transformation, Underlust Sans (Undertale)
Language: English
Status: Completed
Published: 2020-10-18
Updated: 2020-10-18
Packaged: 2021-03-22 04:08:59
Rating: Mature
Warnings: Graphic Depictions Of Violence
Chapters: 1
Words: 2,958
Publisher: archiveofourown.org
Story URL: https://archiveofourown.org/works/30032826
Author URL: https://archiveofourown.org/users/NonstopCreatorOfNonsense/pseuds/NonstopCreatorOfNonsense
Summary: Nep makes a mistake that forever changes his and Gill's lives - possibly for the worst(Part of Nep's origin, back when he and Gill were still a regular Sans and a regular Papyrus)
Relationships: No Romantic Relationship(s), Papyrus & Sans (Undertale)





	In Deep Water

Chest heaving as he gasped for air, the skeleton monster stared at the gruesome scene laid out before him; His favorite human was sprawled out in the snow, their eyes wide, and their face fixed in a clear look of terror. Crimson stained the snow that surrounded them, and from the side of their neck, their upper arm, and shoulder, there were large chunks of their flesh missing. One of their arms was torn clean off their body, and one of their legs had also been mangled and bloodied. Looking down at himself, his eye lights constricted into the smallest of pin pricks, fear taking hold of his entire being as his gaze locked on the blood that stained almost the entire front of his jacket. His slippers were drenched in the scarlet fluid as well, and he let out a strangled cry, his sockets watering up with blue tinted tears. Beginning to tremble, his eye light shifted their focus to his hands, which were covered in the blood of his friend.

There was something that held a metallic taste in his mouth, and as he began to recall what happened, a wave of nausea washed over him. He doubled over, his nonexistent stomach turning. Hitting a certain point, he nearly doubled over, emptying the contents of his stomach into the snow before him. His entire body ached and he broke into sobs, not bothering to wipe the last bit of vomit from his chin. He covered his face with his hands, his shoulders shaking as he began practically wailing, trying desperately to muffle his voice. His soul trembled within his chest, and then small cracks began to form along the edges of it as he choked out, "Oh my god, oh _no…_ oh shit, _what have I done?_ What the hell is _wrong_ with me? Why did I did… I didn’t mean to, I swear. I… I’ve doomed us all, haven’t I?”

Footsteps could be heard crunching in the snow and approaching him, and his feet remained rooted in place as he was greeted by the familiar voice of his younger brother, “SANS? SANS, ARE YOU ALRIGHT?! OH MY WORD, WHAT HAPPENED TO THE HUMAN?!” Sans’ voice was weak, no more than a whimper as he responded, “You gotta get outta here, Pap… It’s not safe.” Ignoring his brother's words, Papyrus approached him from behind, gently placing a hand on his shoulder. Sans flinched at the unexpected contact, his sockets widening, and as he slowly turned to look up at Papyrus, blood staining his clothes and coating the lower half of his face, the younger of the two looked back at him, clearly in shock.

Blue tears rolled down Sans’ cheekbones and he trembled, his voice barely audible, “…I did this, Pap. I’m… I don’t know what’s wrong with me. You need to leave, I don’t wanna hurt you too.” The taller brother sighed deeply, momentarily closing his sockets. Opening them again to look at Sans, he chose to completely disregard the blood on his clothes, leaning down to very delicately wrap his arms around his elder brother, tugging him closer to himself and lowering his voice, “I’m Not Going Anywhere, Brother. Not Without You.” Sans let out another sob, acting on impulse as he latched onto Papyrus, attempting to hide his face.

Their moment was interrupted as another voice pierced the silence, it's tone laced with venom, “ _You_ … Of _all_ the things you could’ve done, you broke the **_ONE_** rule I gave you! Just how _foolish_ are you, Sans?!” Sans whimpered, sniffling and reluctantly peeking at the person who’d addressed him. Immediately recognizing them, his sockets widened again and he turned to fully face them, panic written on all of his features, “I _never meant_ for this to happen, I swear! I didn’t… I didn’t wanna do this. I’m so, _so sorry, please forgive me!_ I’ll do _anything_ to make it right!”

Crossing their arms over their chest, the deity narrowed their eyes, scoffing at his words, “You’re such a half-witted fool. Spilling human blood was the _ONE_ thing that was prohibited! As long as no human blood was spilled, I gave you and your people _COUNTLESS YEARS_ of peace and prosperity. I _protected_ the lot of you, and you’ve taken that for granted!” Sans held his hands up and immediately shook his head, “N-No, I haven’t! Honest! _Please_ , forgive me! I’m begging you!” They merely rolled their eyes, “I cannot, Sans. If I were to let it go this once, who’s to say you won’t do it again, _hm?_ You yourself can’t even be certain of that, can you?” Sans pressed a hand over his mouth, trying to muffle his voice as tears continued pouring from his sockets. Papyrus frowned, clearing his throat and gaining the attention of the deity, “Um… Excuse Me… May I Say Something, Your Greatness?”

The deity nodded, silently giving him their permission to speak. The younger of the two skeleton brothers wasn’t sure what to say or do, but he spoke anyway, his magic beginning to radiate waves of what felt like some sort of hopeful desperation, “I Know My Brother Has Broken A Rule You Set In Place, That Meant The World To You. I Can Assure You Though, He Didn’t _Mean_ To Do This. It’s Not Like Him To Do These Sorts Of Things, I Promise. Just _Look_ At Him… He’s Crying And Pleading With You For Your Forgiveness. If It’s At All Possible, I Humbly Ask That You Look Inside Yourself and Try To Pardon Him. Please. _Just This Once.”_ The divine being arched a single eyebrow, “Are you _defending_ his wrongdoing, Papyrus?” In response, the skeleton in question shook his head, “No No, Absolutely Not. I Agree That It Was _Very Wrong_ Of Him, But Please… Please Forgive Him. Grant Us Your Kindness, And We’ll Make Sure This Never Happens Again.” Sighing, the god rubbed one of their temples, squeezing their eyes shut. The skeleton's remained silent, save for Sans’ broken sobs and whimpers, awaiting their god’s decision.

When the entity opened their eyes and stared at the two with a look of firm resolution, Papyrus felt all the hope in his soul immediately die, shrinking back the smallest bit at their words, “Then _so be it_. If you’d defend him, brother or not, that places you on the same level as him. The two of you are to live out the rest of your days as the terrifying beasts that the humans have come to fear. And since _Sans_ seems to love the taste of human flesh enough to go and violate the single rule I’ve ever given you and the rest of your people, that is the _only_ thing you’ll be able to feast on. It will sustain you, and it’ll be the only food that will give you any sort of satisfaction.” Still sniffling and trying to blink back tears, Sans stared at his bloodied hands, his sockets widening as he watched the tips of his phalanges grow sharper. He opened his mouth, trying to force out a string of words, but froze as his ecto tongue grazed his teeth, feeling how sharp they’d also become. As a second row of serrated teeth began to grow within his mouth, Sans cried out, pain shooting through his face.

His vision went white and he blindly tried to reach for Papyrus, unable to see. Fearing that he’d gone blind, he sobbed, “Pap?… Papyrus, where are you? _Why can’t I see?!”_ Papyrus began to respond, his voice dying in his throat as pain shot through his face, his teeth also beginning to change. When his own vision went white, he was frozen, his own sockets widening and beginning to water up as well. Watching them with a cold, blank expression, their god remained silent, appearing unphased. As the skeletons’ vision began to slowly return, they rubbed their eyes and blinked, once again freezing in place as they saw each other; They’d been given claws, sharpened teeth, and their sockets had gone white, without a single trace of an iris or pupil. Visibly frightened, Sans looked to the deity, “Hey, what’d you do to us?… Why are you punishing Papyrus too, huh?! He didn’t do _anything wrong!”_

They tilted their head, still gazing at him blankly, “Well, didn’t I _just_ say you were to live out the rest of your days as terrifying beasts? You wouldn’t have been terrifying if I left you as you were.” Papyrus blinked, trying to process what just happened. Sockets watering up and orange tinted tears dripping down his cheekbones, he pulled his scarf over his face, filled with shame and fear. He resented the way he looked now, just as he resented the pangs of hunger within him that were urging him to devour the corpse that laid nearby. As the other monsters began to emerge from their homes, Sans’ crime was revealed to them, and his sockets watered up again as he fumbled for an explanation and an apology, watching in horror as their confusion and shock began to morph into disgust and anger. They began to shout at him, and as they began to summon their magic to attack, the crowd parted. Making his way through the gathering, a flamesman silently surveyed the scene before him. Sans looked to him, his voice pleading as he apologized more.

The realization sunk in, as to what would happen now, and Sans felt his blood run cold. Grillby’s flames became hotter, and he cast a wave of fire at the skeletons, offering no hesitation or remorse. He was just as doomed as everyone else. Sans was quick to shortcut out of the path of Grillby’s attack, taking Papyrus with him. Nearly choking as another sob left him, Sans placed himself between Papyrus and the gathering of angry monsters, “Don’t hurt my bro, _please!_ I’m begging you! He’s never done anything to any of you, and he didn’t do anything wrong! He’s not the one who did this, it was me! _I’m_ the one you should dust! Please… Dust me, but leave Papyrus alone. _Please, I’m begging you…”_

A rock was thrown, rocketing toward the shorter of the two skeletons and striking the side of his skull, causing him to cry out as a small crack formed, and as he tried to regain his bearings, a small figure darted through the crowd. He barely had enough time to process what was happening before a knife was drawn and they slashed at him, his sockets widening as tears dripped down his face. His ribs and sternum cracked and chipped under the blade of the knife, and he felt fresh blood begin to drip down his chin. Was that… Was that _his blood?_ No… It couldn’t be. There was no way-

The small figure zipped around him and made a beeline for Papyrus, and he cursed. There was no way in _hell_ they were going to hurt his brother. Something within him snapped and he lunged forward, tackling the human child to the ground. Hunger pulsed through him as he caught the scent of blood again, and he growled lowly, baring his teeth. They were flipped onto their back, and as they immediately tried to slash at him again, his eye twitched and his frown became a wide, crooked grin. He roughly grabbed their wrist, and with a sickening crack and their terrified, pained shrieks, their arm was torn from their body, their hand still clutching the handle of their knife.

He chuckled softly, his voice hoarse as he leaned over them and murmured, “Game over, kiddo. I’d say ’m sorry that it had ta go this way, but that’d be a lie. I _never did_ like ya too much, y'know?” There was another shrill scream that he immediately silenced, his jaws clamping down on their rather thin neck. Serrated teeth now embedded in their flesh, he sharply jerked his head, effectively shredding their throat and destroying any verbal capabilities they had left. He pulled back, looking down at the human beneath him, momentarily horrified at what he’d just done. Tears dripped down his face again and he trembled, hiding his face with his hands. Sans’ mind grew hazy, and his sniffles and sobs shifted, gradually transforming into raspy laughter. A magic attack struck him and he yelped, momentarily surprised, before fixing his gaze on the crowd and narrowing his sockets, his twisted smile stretching across his face again as he rose to his feet. _Oh, they were gonna pay for that._

As another barrage of magic attacks flew toward him, he merely teleported out of their way, trying to ignore pain he felt pulsing through him from his chest each time he moved. Papyrus’ voice gained his attention and he looked up, his smile falling as his sockets went wide and he stared. Water flooded from within the surrounding forest, and as the other monsters caught sight of it, they had the same reaction that he and Papyrus did. Some of them were frozen in fear, and some of them began to run. The water reached the town, crashing full force into the small shops and houses, destroying everything in it’s wake, including whatever monsters who were unable to escape. Most of the towns’ inhabitants were either killed by the impact, or drowned, save for maybe a lucky remaining few, along with Sans and Papyrus.

Instinctively rushing to Papyrus, Sans grabbed onto him, using his magic to maneuver both of them through the water, trying to find the surface. Just as everything seemed to be over, the earth below them began to shake and split open. A second wave of water hit them without a warning, immediately sweeping both of them into the deep pit that’d just been created, and as Sans pushed Papyrus to a more shallow area, adamant that his younger brother try to save himself, one of the remaining monsters appeared. Gripping onto Sans’ jacket, they yelled and cursed at him, roughly shaking him out of anger, and he tolerated this for no more than half a second before he lashed out, turning them to dust.

As if his body was moving against his will, he licked their dust off of his hands, and then was quick to devour their soul, which was all that remained of them. Absentmindedly swaying his feet in the water as he used magic to keep himself in place, he looked around, the reality of the situation finally kicking in. He was horrified and he hated himself for what he did and what he’d become, shaking and erupting into loud, obnoxious laughter. He laughed so hard that tears began to run down his face, and he carelessly discarded his jacket and let it sink as he pressed a hand to his head, his sockets wide and his face fixed into a look of sheer, morbid delight.

Papyrus called out to him and he fell silent, blinking in confusion; His brother cried out for “Sans.” _He_ was Sans… _right?_ Sans the skeleton? That was still him? No, no… It couldn’t be. Not after everything that just happened. Not _now_ that he’d become some sort of _freak._

He shook his head, deciding to abandon his warring thoughts in favor of returning to his brother’s side, right where he belonged. In time, the two very gradually began to adjust to their new lifestyle; While Papyrus lurked at the bottom of their lake and continued making his rounds, just as he did when he was trying to become a member of the royal guard, Sans busied himself with… _Other_ things.

Namely, tracking and hunting, and making sure the both of them were fed. He became detached and separated from his past self, embracing his life as a human eater with open arms. Papyrus wasn’t sure how that was possible; Personally, he _hated_ this new life. He _hated_ always being wet, he _hated_ never feeling clean, he _hated_ the huge lack of puzzle making, and most of all, he _hated_ having to devour innocent humans to survive. To him, the humans were supposed to be their friends, not their food.

They stopped keeping track of how much time had passed, the events that brought them to this new life rapidly shifting into nothing more than a distant, fuzzy memory. One that both of them sometimes struggled to remember, at that. The forest was quiet and peaceful, and Sans took great joy in killing off the humans who entered, both for the sake of getting food, and also for maintaining the peaceful atmosphere. Becoming bored with only hunting humans after a while, Sans took to hunting animals as well. Then, if by some _small chance_ a monster wandered into their forest, he’d cut them down too. Papyrus was horrified, having found his elder brother licking monster dust off his hands and shirt. Eating other monsters was a taboo thing to them, and it had never been discussed before. Papyrus voiced his disagreement with it, trying to get his elder brother to see reason and stop, before he delved too far and indulged in this cannibalistic behavior anymore than he already had.

Sans, being Sans, was stubborn, refusing to stop. Papyrus continued trying to talk him out of it, but gave up after a great while, concluding that there was no point in arguing when Sans refused to listen or take anything into consideration. The two remained just as close as ever despite their obvious differences, and they’d gone on about their lives, just as they’d done before. Everything was normal and fine, and that was the end of it.

That was, until the day a promiscuous skeleton with purple eye lights appeared.


End file.
